Subaru Forester 2004 Service Manual page 193

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTIC)
Step
1 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of throttle position sensor
signal using Subaru Select Monitor or OBD-II
general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE". <Ref. to EN(H4DOTC
2.5)-27, Subaru Select Monitor.>
• OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.
2 CHECK HARNESS BETWEEN TUMBLE
GENERATOR VALVE POSITION SENSOR
AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from throttle
position sensor.
3) Measure the resistance of harness
between throttle position sensor connector and
engine ground.
Connector & terminal
(E50) No. 2 — Engine ground:
3 CHECK HARNESS BETWEEN THROTTLE
POSITION SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between throttle posi-
tion sensor connector and engine ground.
Connector & terminal
(E50) No. 3 (+) — Engine ground (
Check
Is the voltage more than 4.9 V? Go to step 2.
Is the resistance less than 5
Ω?
Is the voltage more than 4.9 V? Repair battery
−
):
EN(H4DOTC 2.5)-192
Yes
Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector
may be the cause.
NOTE:
In this case repair
the following:
• Poor contact in
tumble generator
valve position sen-
sor connector
• Poor contact in
ECM connector.
• Poor contact in
coupling connector
Go to step 3. Repair the harness
and connector.
NOTE:
In this case repair
the following:
• Open circuit in
harness between
tumble generator
valve position sen-
sor and ECM con-
nector
• Poor contact in
coupling connector
• Poor contact in
joint connector
Replace the tum-
short circuit in har- ble generator valve
ness between tum- assembly. <Ref. to
ble generator valve FU(H4DOTC 2.5)-
position sensor 33, Tumble Gener-
and ECM connec- ator Valve Assem-
tor. After repair, bly.>
replace the ECM.
<Ref. to
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>
No